LONDON, England (CNN) -- He immortalized the "smell of napalm in the morning" in "Apocalypse Now," but Robert Duvall's first meeting with director Francis Ford Coppola was no indication of the fruitful relationship to come.

Duvall starred in Francis Ford Coppola's "The Godfather," "The Godfather: Part II" and "Apocalypse Now."

It was 1969 and Coppola had parted ways with a lead character in indie film "The Rain People." He was stuck and 38-year-old Duvall was drafted in at the last minute on the suggestion of a friend.

Despite slapdash beginnings, their work together has produced some of Duvall's greatest roles and many of Coppola's most critically-acclaimed films.

Duvall started working in theater in the 1950s before moving into film in the early 1960s with roles like Boo Radley in "To Kill a Mockingbird."

Things took off for him in 1970s when he starred in Coppola's multiple award-winning movies "The Godfather" and "The Godfather: Part II,"

But, it is his Oscar-nominated turn as indestructible, napalm-loving Lt. Colonel Kilgore in Coppola's Vietnam war opus "Apocalypse Now" that remains one of Duvall's most enduring roles.

Duvall sits down with CNN's Revealed and talks about, "Apocalypse Now" and his relationship with the master movie-maker.

Revealed: Can you sum up the impact Coppola had on your life, your career?

RD: I would have had another career. He helped all our careers with "The Godfather." It was a kind of catalyst for all the actors in one and two. It helped me. I kinda designed my own career.

Revealed: What's Coppola's approach to directing?

RD: Ithink sometimes Francis works best amidst confusion and I mean that in a good way. He'll come in and say, 'Let's try something,' and then you rehearse. Like any good director he sees what you bring. He realizes it's gotta come from the actor. He's open enough ... of course, he'll give his opinion but he wants to see what you bring.

Revealed: The problems Coppola encountered while shooting "Apocalypse Now" are legendary. What was it like working on that film?

RD: There are things I won't go into! But it was pretty crazy. Sometimes we'd get one shot in a day, if that. Everything was in disarray. The hurricane came in and ruined the sets, s**t! Then they had to build them again, and we were there nine or 10 months. Dennis Hopper all doped up, not doing it Francis' way. Francis would do 45 takes, and then he said, 'Now, would you please do one my way," he'd say to Dennis. Martin Sheen got the heart attack, and they didn't know what they would do if they lost Martin. Francis said it was like warfare. Watch Coppola and others talk about the making of "Apocalypse Now" »

Revealed: You say that people constantly come up to you in the street and say the line, 'I love the smell of napalm in the morning.'

RD: It is a pretty famous line. Everybody relates to that line. Scenes like that we had to get quickly because all that fire at the back of me was supposed to be the napalm. Sometimes when you work fast and under duress ... sometimes that's the best stuff you can get.

Revealed: How did your life change after "Apocalypse Now," and the "Godfather" films came out?

Revealed: What is it about Coppola that makes him such a great director?

RD: A guy like Coppola, you know, as a director, he wants to see what you bring, without dictating. He's not a dictator. He has a definite vision, but he's not going to get in there and say it has to be my way or the highway. He really wants to see what you bring. He'll say, 'Come on guys quit fooling around we gotta make a movie!' You branch off into laughing and making jokes, but that's good for the set and he knows that too. It's his own gift and it's his own way of working.

Revealed: Coppola says now he wants to make small, intimate movies he has written himself. What's your take on that?

RD: He's a big spender. Now he's making all the wine and everything else, he can go back to independent film. Why not? He said "The Conversation" was his favorite film. It was certainly one of his best, I think. Why not go back to what he started out as? In the 1970s it was as if the independent filmmaking community was within the establishment. Now it's back outside the establishment starting to make the kind of films he started out doing.

Revealed: Can you describe Francis in a few words?

RD: A talented maniac. No, no, not a maniac, but he's a talented, driven guy. He's a heavy hitter.